Power line for antenne



F. GERTH POWER LINE FOR ANTENNFE Filed Dec. 20, 1932 A my:

f]? 14. 221 021- f/n? Ger/V7 y MM iii 0N2 ey Patented June 26, 1934 UNITED STATES POWER LINE FOR AN TENNZE Felix Gerth, Berlin-Tempelhof, Germany, assignor to C. Lorenz Aktiengesellschaft, Berlin- Tempelhof, Germany Application December 2 In Germany 3 Claims.

In the high frequency art, as is well known, at.

the various stations so-called power or transmission lines are employed, which usually consist of two parallel conductors. These are traversed in phase opposition by the high frequency to be transmitted, so that the external fields are cancelled and therefore there is no radiation. It may, however, happen that the conductors are also traversed by co-phasal currents in addition to the currents in phase opposition. This is the case, for example, with lines which serve to feed antenna systems. In this case the line is situated in the field of the radiating antennae. The closely adjacent conductors of these power lines are induced by this field in the same direction, so that on account of such radiation-coupling co-phasal currents flow. These currents cause the power line to radiate and thereby the directional characteristic of the antenna arrangement may be undesirably infiuenced. It is the object of the present invention to control these co-phasal currents. According to the invention these co-phasal currents are prevented from flowing or are neutralized, or their current loop is so located that the radiation characteristic of the antenna arrangement is improved or a desired radiation diagram is obtained.

Several embodiments of the invention are shown in the accompanying drawing. Figure 1 is a schematic elevation of one of such embodiments, Figure 2 the ground plan of a second embodiment. Figure 3 is a diagram of a third embodiment. Figure 4 is a schematic elevation of a fourth embodiment.

In the arrangement shown in Figure 1, an antenna A of any antenna arrangement is fed from the transmitter S over the power line E. In the middle of the line E is inserted a coil arrangement L that consists of two interwound coils, which are wound in the same direction and are closely coupled together. One of these coils is inserted in each of the two conductors of the line E. The inductances of these coils neutralize one another for the counter-phasal currents coming from the transmitter so that in this desired direction the power can fiow unhindered. With the co-phasal currents induced by the radiation of the antenna A, however, the inductances are added, so that the currents find a resistance which does not permit them to flow.

The coils L may be repeated in the line E at certain intervals, which are preferably equal.

Figure 2 shows a horizontal fiat antenna struc ture comprising a central emitter Z and outer emitters A, which surround the emitter Z and 0, 1932, Serial No. 648,079

May 31, 1932 are supplied with power from the centre of this structure. The centre is connected through a power line B with the transmitter S. Power lines H also extend from the transmitter S to each of the power lines E for the sake of simplicity, only one of such lines H is shown. This is so coupled with its line E at G and with the transmitter S that the current transmitted by the line H is of correct phase and amplitude for the suppression of the co-phasal currents in the line E. According to the circumstances the co-phasal energy in both conductors of the energy line E may thereby be suppressed, or within certain limits an asymmetry may be allowed by suppressing the cophasal currents only in that conductor of the power line E in which the co-phasal current is opposed to the co-phasal current from the transmitter S.

In the embodiment shown in Figure 3 a certain combination of the lines E, H is shown. Power is conveyed from the line E over a coupling arrange ment K, to a device V where a phase displacement is eifected. In the output circuit of the phasechanging device V, is the coupling arrangement G, by which the compensation is effected in the same manner as in the arrangement according to Figure 2. The energy for compensating is thus obtained from the line E itself.

In the device according to Figure 4 the antenna A consists of dipoles D, whose centres of radiation are situated at V4 height above the ground. A represents the wave-length. In the line over which the transmitter S feeds the dipoles, tuning means A are inserted, which are so arranged that the current loop of the co-phasal currents is situated as near as possible to the dipoles. Thereby the co-phasal currents produce a field in the line E outwards, which is approximately identical with the field generated by the dipoles D. In this manner the radiation fields of the dipoles and of the line E may be made more or less to coincide and consequently the radiation characteristic of the antenna arrangement is improved and undesired field distortions are substantially avoided.

The current loop of the co-phasal currents need not necessarily coincide with the radiation centres, but may, for example, be placed in the vicinity of the earths surface. In this manner by a suitable choice of the phase, that is by a certain construction of the line E or by the insertion of phase shifting means, amplification of the radiation diagram is obtained in a similar manner as though a short vertical conductor were situated on the ground, and tuned in conjunction with earth. Thus any desired intensification of the radiation diagram may be obtained.

What is claimed is:

1. In a power line for antennae that consists of conductors parallel to each other, the combination with an antenna structure of means for causing counter-phasal currents to flow in these conductors, and means for locating the current loop of the co-phasal currents in the vicinity of the radiation centre of said antenna structure and for causing the direction of the co-phasal currents adjacent the antenna structure to be such as to augment the radiation field thereof.

2. In a power line for antennae which consists of conductors parallel to one another, the combination with an antenna structure of means for causing counter-phasal currents to flow in these conductors, and means for locating the current loop of the co-phasal currents at a point which is distant from the radiation centre of the said antenna structure.

3. In combination, an antenna structure, a transmission line in the radiation field of said antenna structure and comprising parallel conductors, means for supplying high frequency currents over said transmission line to said antenna structure, and means for so locating the loop of and phasing the co-phasal currents induced in the conductors of said transmission line with respect to the current in the antenna structure as to improve the radiation characteristic of the antenna structure.

FELIX GERTH. 

